Method of and apparatus for mining gold or other metals



(No Model) A. McDOUG-ALL.

METHOD GP AND APPARATUS FOR MINING GOLD OR OTHER METALS No. 531,740.Patented Jan. 1,1895.

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NITED TATES ALEXANDER MODOUGALL,

OF- DULUTH, MINNESOTA.

METHOD OF AND APPARATUS FOR MINING GOLD OR OTHER METALS.

SPECIFICATION forming part of Letters Patent No. 531,740, dated January1, l 89 5.

Application filed June 18, 1894.

1'0 zc-ZZ whom it may concern.-

Be it known that I, ALEXANDER McDon- GALL, a citizen of the UnitedStates, residing at Duluth, in the county of St. Louis and State ofMinnesota, have invented certain new and useful Improvements in Methodsof and Apparatus for Mining Gold or other Metals; and I do herebydeclare the following to be a full, clear, and exact description of theinvention, which will enable others skilled in the art to which itappertains to make and use the same.

lily invention relates toa method of and apparatus for mininggold andother metals, found in mineral bearing sand and gravel forming part ofriver and lake bottoms.

The bottoms of many of the American rivers and lakes, particularly inthe Northwest, contain considerable quantities of sand, earth and gravelin which are found gold, silver,copper and other metals and which I willhereinafter refer to by the generic expression, mineral bearing sand andgravel. These metals are either chemically combined with the sand andgravel or are mechanically mixed therewith. It is now the generalpractice to remove this mineral bearing sand from the bottom of riversand lakes by suction produced by contrifugal or other pumps, after whichit is drained of water and finally is treated for the removal of theparticular metal desired in any well known way. It has however beendiscovered that this mineral bearing sand or gravel is frequently foundto be mixed with heavy stones, rocks, boulders and other obstructions,which not only tend to clog up the suction pipes and damage the workingparts of the pumps, but render it impossible to handle such sand andgravel with economy, so that when the mineral bearing sand and gravelare found to be mixed with obstructions of the character mentioned, noefforts are made to remove it, although it may be rich in minerals.

My present invention relates to a method of and apparatus for removingthese heavy rocks, stones, boulders and other obstructions, so that themineral bearing sand and gravel with which they are mixed, can bereadily mined by a centrifugal or other pump.

For a better comprehension of the inven- Serial No. 514.972- (Nu model.)

tion, attention is directed to the accompanying drawings, in whichFigure l is a side elevation of my improved apparatus showing the bed ofthe river or lake in section, and Fig. 2, a plan view of the ap .paratuson an enlarged scale.

Referring to the views, A, is a Hat boat or scoW made preferably of theform illustrated, namely, with its sides inclined toward each other fromthestern to the bow. It is to be observed h0wever,that any otherconstruction form to the configuration of the river or lake bottom; is arake B, provided with heavy teeth a, s0 arranged with respect to eachother that they will engage and remove all stones or rocks which are ofa size sufficiently large to damage the working parts of the pumps orobstruct the suction pipes thereof. I do not desire to be limited to anyparticular mechanism for carrying this rake, or to any particular devicefor raising and lowering it, yet the means illustrated for aocomplishing these ends which I shall now describe, can be advantageousl y used.

Pivoted to each side of the scow A, preferably at a point a shortdistance back of its central axis, c'. e. at about its center ofgravity, is a heavy arm 0, made either of wood or metal. These two armsextend parallel with the sides of the scow and if the latter is of theconfiguration illustrated, these arms will converge toward each other asshown, whereby a rake of reasonable Width, say from six to eight feet,may be attached in any desirable way directly to the free ends of thesearms. By pivoting these arms 0, at a point back of the central axis ofthe scow it will be observed that very long arms can be employed forworking in considerable depths of water and at the same time the entireresist- IOC . ance of the rake is imposed upon the scow at about itscenter of gravity, as explained,

whereby the scow will always preserve its line of flotation under allconditions. Furthermore, by so arranging these arms the rake will workin the river bottom at a point imafter referred to.: The arms 0,carrying the rake B, may be elevated 'or lowered inany suitable way,preferably by a cable 0, passing over a block d, carried by a supportingarm c, said cable being operated by a windlassf, supplied with steamfrom the boiler or operated by hand. In order that the scow-A,car-:rying the rake B, may be moved with respect -to the river bottom, Iprefer to make useof a heavy'cable. G, which may be anchored at bothends, as shown, or be attached to stakes or posts, said cable beingpassed. over sheaves H, preferably beneath the deck of the scow,

and thence 'aroundthe drum of a steam windlass 1 by which thesaid scowmay bepropelled.

With this apparatus I proceed to carry out my invention substantially asfollows: The

cable G, is first arranged with respect to that portion of the river bedin which are found mineral bearing sand and gravel mixed with heavyrocks, stones and other obstructions, said cable passing through thescow, as explained, and over the drum of the steam Windlass 'i. The rakeB, is now lowered, being preferably allowed to drag freely along theriver bottom and the Windlass 1', is started so that the scow will bepropelled along the line of the cable G, dragging the rake B, along theriver bed and raking up and carrying with it allthe heavy rocks, stonesand other obstructions. The scow is then returned to the starting pointand this operation is repeated until the mineral bearing sand and gravelare free from all obstructions, the cable G, being shifted slightly toone side as the work pro- Stay rods Z), I), may be used for the gresses,if desired, after which the cable G,is

removed to another part of the river and the operation is repeated.After the river orlake bottom has thus been freed of such obstructionsas are not removable by suction, the mineral bearing sand or gravel isremoved by suction, and the particular metal recovered therefrom inanydesirable way.

. Broadly considered, my improved method consists in removing largestones, rocks,

b ouldersand other obstructions from mineral bearing sand and gravel andthen in removthan those I have described and illustrated forpropellingthe scow may be availed of.

For example, the scow may be moved with respectto the cable G, by a handWindlass or capstan, or it may be provided with independe out means ormechanism, such as a screw, or I it may be moved by a separatepropelling I claim as newtherein, and desire to secure by.

Letters Patent, is as follows:

1. The method of mining gold and other metalscontained in mineralbearing sand and gravel forming part of lake and river bottoms, whichconsists in removing by the action of rake teeth such coarse rocks andother obstructions as are not removable by suction, and then in removingthe mineral bearing sand or gravel thus freed from'obstructions,bylsuetion, substantially as set forth. I

2. In an appar tus of the characterrdescribed, the combination of afloating vessel A, having its sides inclined from bow to stern, the arms0, pivoted to said sides and converging toward each other at the rearend, and a rake B, carried by said arms in the rear of the vessel andcapable of vertical movement, substantially as set forth.

In testimony whereoflaffix my signature in presence of two witnesses.

I ALEXANDER MODOUGALL.

'Witnesses:

S. GEO. STEVENS, CHAS. W. LELAND.

